Hi, I've been trying to set up a windows 7 virtual machine to do vga passthrough, using the q35 machine as a base. The setup seems to be working nice except than, when removing the emulated vga, libusb drops the usb devices with an error close to this:
qemu-system-x86_64: libusb_release_interface: -4 [NO_DEVICE] libusb: error [_open_sysfs_attr} open /sys/bus/usb/devices/3-5/bConfigurationValue failed ret=-1 errno=2 qemu-system-x86_64: libusb_release_interface: -4 [NO_DEVICE] libusb: error [_open_sysfs_attr} open /sys/bus/usb/devices/4-1/bConfigurationValue failed ret=-1 errno=2 Disabling IRQ #18 Disabling IRQ #17 I'm using qemu-2.2.1, and if I try to use any version higher, this error happens even in 440fx machines. Kernel is 4.1.8. The script I use to launch is the following: qemu-system-x86_64 -enable-kvm -M q35 -vga none -cpu host -smp 3,cores=3,threads=1 -m 6144 \ -L /usr/x86_64-pc-linux-gnu/usr/share/qemu \ -device ioh3420,multifunction=on,id=pcie \ -device vfio-pci,host=01:00.0,x-vga=on,multifunction=on,bus=pcie \ -device vfio-pci,host=01:00.1,bus=pcie \ -netdev user,id=user.0 -device virtio-net-pci,netdev=user.0 \ -usb -usbdevice host:03f0:134a -usbdevice host:03f0:0024 -usbdevice host:0079:0006 \ -drive file=q35_win7.img,format=raw,cache=none,aio=native,if=virtio From the system log I can get the following: Oct 12 19:45:36 koalita kernel: usb 3-5: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:36 koalita kernel: usb 4-1: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:37 koalita kernel: usb 10-2: reset low-speed USB device number 2 using xhci_hcd Oct 12 19:45:37 koalita kernel: usb 10-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:37 koalita kernel: usb 10-2: ep 0x1 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:37 koalita kernel: usb 4-1: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:38 koalita kernel: usb 3-5: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:38 koalita kernel: usb 10-2: reset low-speed USB device number 2 using xhci_hcd Oct 12 19:45:39 koalita kernel: usb 10-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:39 koalita kernel: usb 10-2: ep 0x1 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:39 koalita kernel: usb 3-5: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:40 koalita kernel: usb 4-1: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:40 koalita kernel: usb 3-5: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:41 koalita kernel: usb 10-2: reset low-speed USB device number 2 using xhci_hcd Oct 12 19:45:41 koalita kernel: usb 10-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:41 koalita kernel: usb 10-2: ep 0x1 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:41 koalita kernel: usb 10-2: reset low-speed USB device number 2 using xhci_hcd Oct 12 19:45:42 koalita kernel: usb 10-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:42 koalita kernel: usb 10-2: ep 0x1 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:42 koalita kernel: usb 4-1: reset low-speed USB device number 2 using ohci-pci Oct 12 19:45:44 koalita kernel: kvm: zapping shadow pages for mmio generation wraparound Oct 12 19:45:47 koalita kernel: ata2: illegal qc_active transition (00000020- >ffffffff) Oct 12 19:45:47 koalita kernel: ohci-pci 0000:00:13.0: HC died; cleaning up Oct 12 19:45:47 koalita kernel: usb 4-1: USB disconnect, device number 2 Oct 12 19:45:47 koalita kernel: ohci-pci 0000:00:14.5: HC died; cleaning up Oct 12 19:45:47 koalita kernel: ohci-pci 0000:00:12.0: HC died; cleaning up Oct 12 19:45:47 koalita kernel: usb 3-5: USB disconnect, device number 2 Oct 12 19:45:47 koalita kernel: ata2.00: exception Emask 0x2 SAct 0x20 SErr 0x0 action 0x6 frozen Oct 12 19:45:47 koalita kernel: ata2.00: failed command: READ FPDMA QUEUED Oct 12 19:45:47 koalita kernel: ata2.00: cmd 60/08:28:c8:6a:04/00:00:1f:00:00/40 tag 5 ncq 4096 in\x0a res 40/00:2c:c8:6a:04/00:00:1f:00:00/40 Emask 0x2 (HSM violation) Oct 12 19:45:47 koalita kernel: ata2.00: status: { DRDY } Oct 12 19:45:47 koalita kernel: ata2: hard resetting link Oct 12 19:45:47 koalita kernel: usb 10-2: reset low-speed USB device number 2 using xhci_hcd Oct 12 19:45:47 koalita kernel: ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Oct 12 19:45:47 koalita kernel: ata2.00: configured for UDMA/133 Oct 12 19:45:47 koalita kernel: ata2: EH complete Oct 12 19:45:47 koalita kernel: usb 10-2: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:47 koalita kernel: usb 10-2: ep 0x1 - rounding interval to 64 microframes, ep desc says 80 microframes Oct 12 19:45:47 koalita kernel: input: Microntek USB Joystick as /devices/pci0000:00/0000:00:03.2/0000:03:00.0/usb10/10-2/10-2:1.0/0003:0079:0006.0004/input/input19 Oct 12 19:45:47 koalita kernel: dragonrise 0003:0079:0006.0004: input,hidraw0: USB HID v1.10 Joystick [Microntek USB Joystick ] on usb-0000:03:00.0-2/input0 Oct 12 19:45:47 koalita kernel: dragonrise 0003:0079:0006.0004: Force Feedback for DragonRise Inc. game controllers by Richard Walmsley <richw...@gmail.com> Oct 12 19:45:47 koalita kernel: ata2.00: exception Emask 0x33 SAct 0x28400 SErr 0x0 action 0xe frozen Oct 12 19:45:47 koalita kernel: ata2.00: irq_stat 0xffffffff, unknown FIS 00000000 00000000 00000000 00000000, host bus Oct 12 19:45:47 koalita kernel: ata2.00: failed command: READ FPDMA QUEUED Oct 12 19:45:47 koalita kernel: ata2.00: cmd 60/08:50:c8:6a:04/00:00:1f:00:00/40 tag 10 ncq 4096 in\x0a res 40/00:8c:a8:52:c3/00:00:03:00:00/40 Emask 0x32 (host bus error) Oct 12 19:45:47 koalita kernel: ata2.00: status: { DRDY } Oct 12 19:45:47 koalita kernel: ata2.00: failed command: READ FPDMA QUEUED Oct 12 19:45:47 koalita kernel: ata2.00: cmd 60/20:78:60:73:c3/00:00:03:00:00/40 tag 15 ncq 16384 in\x0a res 40/00:8c:a8:52:c3/00:00:03:00:00/40 Emask 0x32 (host bus error) Oct 12 19:45:47 koalita kernel: ata2.00: status: { DRDY } Oct 12 19:45:47 koalita kernel: ata2.00: failed command: READ FPDMA QUEUED Oct 12 19:45:47 koalita kernel: ata2.00: cmd 60/08:88:a8:52:c3/00:00:03:00:00/40 tag 17 ncq 4096 in\x0a res 40/00:8c:a8:52:c3/00:00:03:00:00/40 Emask 0x32 (host bus error) Oct 12 19:45:47 koalita kernel: ata2.00: status: { DRDY } Oct 12 19:45:47 koalita kernel: ata2: hard resetting link Oct 12 19:45:47 koalita kernel: irq 18: nobody cared (try booting with the "irqpoll" option) Oct 12 19:45:47 koalita kernel: CPU: 3 PID: 0 Comm: swapper/3 Tainted: G O 4.1.8 #1 Oct 12 19:45:47 koalita kernel: Hardware name: MSI MS-7721/A88XM-E45 (MS-7721), BIOS V25.6 12/15/2014 Oct 12 19:45:47 koalita kernel: ffff880245efce8c ffff88024ed83df8 ffffffff814c840e 0000000000040400 Oct 12 19:45:47 koalita kernel: ffff880245efce00 ffff88024ed83e28 ffffffff81093b98 ffff88024ed83e28 Oct 12 19:45:47 koalita kernel: ffff880245efce00 0000000000000000 0000000000000012 ffff88024ed83e68 Oct 12 19:45:47 koalita kernel: Call Trace: Oct 12 19:45:47 koalita kernel: <IRQ> [<ffffffff814c840e>] dump_stack+0x45/0x57 Oct 12 19:45:47 koalita kernel: [<ffffffff81093b98>] __report_bad_irq+0x38/0xe0 Oct 12 19:45:47 koalita kernel: [<ffffffff81093f26>] note_interrupt+0x246/0x290 Oct 12 19:45:47 koalita kernel: [<ffffffff810915a3>] handle_irq_event_percpu+0x123/0x190 Oct 12 19:45:47 koalita kernel: [<ffffffff8100c0e2>] ? native_sched_clock+0x32/0x90 Oct 12 19:45:47 koalita kernel: [<ffffffff81091653>] handle_irq_event+0x43/0x70 Oct 12 19:45:47 koalita kernel: [<ffffffff810a12d3>] ? hrtimer_start+0x13/0x20 Oct 12 19:45:47 koalita kernel: [<ffffffff81094338>] handle_fasteoi_irq+0x88/0x140 Oct 12 19:45:47 koalita kernel: [<ffffffff81004e24>] handle_irq+0x74/0x130 Oct 12 19:45:47 koalita kernel: [<ffffffff81061635>] ? atomic_notifier_call_chain+0x15/0x20 Oct 12 19:45:47 koalita kernel: [<ffffffff810046a5>] do_IRQ+0x55/0x100 Oct 12 19:45:47 koalita kernel: [<ffffffff814cea2e>] common_interrupt+0x6e/0x6e Oct 12 19:45:47 koalita kernel: <EOI> [<ffffffff810adb88>] ? clockevents_program_event+0x78/0x110 Oct 12 19:45:47 koalita kernel: [<ffffffff81032e66>] ? native_safe_halt+0x6/0x10 Oct 12 19:45:47 koalita kernel: [<ffffffff810a115c>] ? __hrtimer_start_range_ns+0x2bc/0x400 Oct 12 19:45:47 koalita kernel: [<ffffffffa02c534a>] arch_safe_halt+0x9/0xd [processor] Oct 12 19:45:47 koalita kernel: [<ffffffffa02c5b7c>] acpi_safe_halt+0x1d/0x26 [processor] Oct 12 19:45:47 koalita kernel: [<ffffffffa02c5ba0>] acpi_idle_do_entry+0x1b/0x2b [processor] Oct 12 19:45:47 koalita kernel: [<ffffffffa02c5e76>] acpi_idle_enter+0x19c/0x1be [processor] Oct 12 19:45:47 koalita kernel: [<ffffffff813df1a0>] cpuidle_enter_state+0x80/0x200 Oct 12 19:45:47 koalita kernel: [<ffffffff813df342>] cpuidle_enter+0x12/0x20 Oct 12 19:45:47 koalita kernel: [<ffffffff81080041>] cpu_startup_entry+0x371/0x3f0 Oct 12 19:45:47 koalita kernel: [<ffffffff81024b5d>] start_secondary+0x16d/0x180 Oct 12 19:45:47 koalita kernel: handlers: Oct 12 19:45:47 koalita kernel: [<ffffffff8137c240>] usb_hcd_irq Oct 12 19:45:47 koalita kernel: [<ffffffff8137c240>] usb_hcd_irq Oct 12 19:45:47 koalita kernel: [<ffffffff8137c240>] usb_hcd_irq Oct 12 19:45:47 koalita kernel: Disabling IRQ #18 Any insight? Thanks! José.